1. Technical Field
The present disclosure generally relates to an optical film. Particularly, the present disclosure relates to an optical film having light-output microstructures arranged in a periodic manner and a display device having the optical film.
2. Description of the Prior Art
In recent years, flat display devices have been widely used in a variety of fields as an independent display device or embedded in electronic devices for displaying information. There are all kinds of flat display devices including, for example, organic light-emitting diode display device, liquid crystal display device, electrophoretic display device, etc. Among them, liquid crystal display device is the most common flat display device.
For liquid crystal display device, the operation principle is to utilize the orientation of liquid crystal molecules in the liquid crystal display panel to control the transmission of backlight for each pixel so as to display images on the display face of the liquid crystal display device. In order to increase the viewing angle of the liquid crystal display device, i.e. the angle between the eyesight of viewer and the normal direction of the display face of the liquid crystal display device, a conventional way is to attach an optical film onto the display face of the liquid crystal display device. In addition, for other purposes, such as secrecy and privacy protection, an additional optical film can be attached onto the display face. In particular, for display devices using the blue phase liquid crystal (BPLC) panel, in order to enhance the optical effect, an optical film is usually attached onto the display face. However, the design of conventional optical films is very complicated. For example, two optical films with corresponding structures must align and overlap with each other, so the manufacturability is relatively low.